As safety concerns for rail systems become an increasingly important public issue, a need has arisen for implementing an automated control system, such as positive train control (PTC), which incorporates automated systems and processes for controlling a train. The systems include onboard equipment capable of data communication with offboard equipment. The onboard equipment generally includes a train management computer (TMC) configured to impart control over the train and communicate with the offboard equipment via a radio. The radio receives and forwards messages from offboard equipment to the TMC. The radio also receives and forwards messages from the TMC to the offboard equipment. In this way, automated remote management of a rail system may be possible.
While various wireless communication technologies may facilitate communication between the offboard equipment and onboard radio, the train's mobile and constantly changing environment may, at times, make wireless communications unreliable. If the wireless communication is not sufficiently reliable, the automated control system cannot be implemented efficiently. Further, significant reliance is placed on each radio to function properly. If a radio fails, the automated control system cannot be operated because of the risk of messages going undelivered. Further, possible solutions requiring modifications to currently-existing train components (e.g., TMC and/or radios) may be expensive and/or difficult to implement.
One system implementing PTC is described in U.S. Patent Application Publication 2012/0123617 to Noffsinger et al. (“the '617 publication”). The PTC system of the '617 publication includes computing systems on multiple rail vehicles that can communicate with each other through more than one pathway. The communication can occur through a wireless network provided by a wayside device. In particular, if a direct radio link between first and second rail vehicles is unavailable, a data communication can be sent between the first and second rail vehicles via the wireless network provided by the wayside device.
While the communication system described in the '617 publication may create new communication pathways, it may be subject to the same drawbacks associated with wireless communication, including unreliability and increased use of bandwidth. The system described in the '617 publication may increase reliance on radio communication, which remains problematic if the radio fails. Further, implementation of the described system may require modifications to existing computing systems and installation of new wayside equipment to allow for communication via the wayside wireless pathway, increasing costs and complexity.
Some offboard communication systems may address reliability by utilizing data forwarding between various wayside equipment modules. For example, some offboard equipment modules may be configured to share inbound and outbound communications with each other. While these wayside systems may address some offboard equipment concerns, they do not improve the reliability of onboard communication systems.
The present disclosure is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.